If you operate a turbo prop to the same airport as single engine training aircraft most schools teach their students to overfly at circuit + 500, so thats smack in to the turbo prop circuit pattern.
Its not fun trying to convince the student that they are not clear of you just because they are overflying at 1500 AGL.
So why dont we give up with the 1500 circuit and drop to a 1000, its safer that way.
I would love to know who dreampt up the change and why?
